Three polio eradication workers, including two women, were shot dead by armed men on motorcycles during a vaccination drive on Tuesday in Qayyumabad, eastern Karachi.
In another attack, at least seven people were killed and nine others were injured in an explosion near a police mobile van which was on its way for security duty for polio immunisation workers in Khyber Pakhtunkhwa's Charsadda district on Wednesday.
The dead included six policemen and a bystander child.